Barrel-cooling device for firearms



April 24, 1928.

J. M. BROWNING BARREL COOLING DEVICE FOR FIREARMS fnvsntaz" Filed Oct,

Patented Apr. 24, 1928.

UNITED STATES PATENT OFFICE.

.TonN M. BROWNING, or OGDEN, UTAH; Jorr BROWNING ADMINISTRATOR or sun JOHN M. BROWNING, DECEASED.

BARREL-COOLING DEVICE FOR FIREARMS.

Application filed October 15, 1925. Serial- No. 62,672.

The invention relates to'a barrel cooling device for automatic machine guns having a recoiling barrel, and more particularly to a device of this kind in which water 1s used as the cooling medium.

In machine guns of this class a tubular water cooling jacket surrounds the barrel and is suitably connected at its rear end to the breech casing of the gun. At the front, the jacket is provided with a closing cap having a bore within which the barrel slides- To prevent leakage of water along the barrel suitable stuffing boxes are provided at the rear end and at the front closing cap of the jacket.

After using such a gun, the water must be drained from the jacket and the barrel cleaned and greased to prevent its rusting.

Failure to effect this cleaning operation mayresult in the subsequent malfunctioning of the gun due to the rusted condition of the barrel which particularly interferes with the smooth movement of the barrel and tends to tear the packing in the front and rear stuff ing boxes with'a resultant leakage of the waterfrom the casing. Heretoforeithas been necessary, in order to effect this necessary cleaning and treatment of the barrel,

to open the rear end of the breech casing,

remove the mechanism in rear of the barrel and to finally withdraw the barrel from the water jacket and breech casing in rearward direction.

It is an object of my invention to provide a construction whereby ready access canbe" had to the barrel for this purposewithout.

the necessity of handling the barrel by dismounting it from the gun. Such a construction is particularly desirable in guns of rel-" atively large caliber (say- 37m/m or over) because of the weight of the barrel. This object is attained by providing a water cooling casing which can be easily attached to and detached from the breech casing and slid forwardly off the barrel, after which the barrel can be cleaned in situ.

A further object of the invention resides in the provision of means whereby the used packing in the stufing boxes can also be readily removed and new'packing inserted. In automatic machineguns of this class, it has also been found that the extreme forward portion of the'barrel, which necessarily projects forwardly beyond the front closing cap of the water jacket a distance substan It is,'therefore, a further ob ect of'the invention to provide for the more effective cooling of the barrel at its forward portion, and this object is attained by providing means for preventing the drop vofthe'level of the Water in the forward portion of the.

jacket when the gunrisat a high elevation,

and during the recoil and return movements.

of the barrel, thereby. insuring that the forward portion of the barrel is sufficiently subj ected to the cooling action of the water.

In the accompanying drawings. there is shown a preferred embodiment of the invention as applied to an automatic gun of'large caliber, such as is shown and described, for example, 1n my prior Patent, N0.;1,525,065

dated February ,3, v1925, for an automatic firearm, but'it willbeiobvious. thatit is equally applicable to other guns and to guns of smaller caliber.

In the drawings:

Fig. 1 is the partial left side elevation of the. gun having mounted thereon a cooling device embodying the invention;

Fig. 2 is a front elevation of the forward portion of the gun and-cooling device mount ed thereon;

Fig. 3 is a verticallongitudinal section of the forward portion of the-gun with parts broken away i 1 Fig. 4 is an enlarged front elevationof the front stufilng box and the hose connection therefor, theibarrel being shown in sect-ion;

Fig. 5 is an enlarged central longitudinal vertical section through the front stufiing box;

' Fig. section taken on the line 6-.-6 of Fig. 3, show- 'ing the novel check'valve for holding the water inthe extreme forward portion of the 6 is an enlarged vertical transverse;

casing when gun is elevated to high angles;

tor 4.

section taken on the line 88'of Fig. 3 showing the positions of rear hose connection and rear stuifing box; and

Fig. 9 is an enlarged partial vertical longitudinal section and elevation of the gun showing therear stutfing box, recoil spring, and means for readily releasing the water jacket from the gun casing.

The following main parts of the gun shown and described in Patent No. 1,525,065 are shown in the drawings; the breech casing l, trunnion block 2, barrel 3 and recupera- In the gun'to which the invention is shown applied, the rear portion of the long slidable barrel 8 is supported and guided in a seat in the trunnion block 2 closingvthe front end of the breech casing 1. The barrel 3 is preferably tapered in accordance with the customary practice,

As clearly shown in the drawings, there is provided a water jacket 5- which surrounds the barrel 3. Preferably the internal diameter of the tubular jacket 5 is but slightly larger than the external diameter of: the rear portion of the barrel and surrounds the same from the breech casing forward to a point some distance rearward of the muzzle of the barrel. This small diameter ofthe cooling jacket is desirable to avoid unnecessarily increasing the weight of the un and the water is conveniently supplied to the jacketv through a port 6 at the rear end of the tubular casing and leaves the jacket through a similar port 7 at the top of the forward portion of the jacket, the said ports being respectively provided with suitable fixtures 6 and 7. The continuous or substantially continuous supply of cold water to the jacket is assured by the provision of an external reservoir (not shown) from which the water is pumped through a conduit to the jacket and, if desired, the warmer water leaving the jacket may again be led back to the reservoir through a flexible conduit 8. Obviously, other suitable means for circulating the coolmg water through the jacket bringing it into contact with the barrel might be used, the manner in which the circulation of the water is effected forming no part of the present invention.

To provide a readily detachable connection for the water jacket to the breech casing of the gun so as to permit its convenient removal I provide a suitable connecting-means which is operative while the casing is held against rotative movement, the said means serving to draw the casing rearward into its proper relationship with the breech casing. It will be obviousthat the avoidance of rotary movement is highly important as otherwise the hose connections would have to be removed before the jacket would be detached. Y

A suitable means such as a s tuifing box is provided for preventing the leakage of water from the water jacket into the breech casing and preferably this stufiing box is so arranged that it can be adjusted while the jacket is secured to the casing as already stated.

Preferably and as shown the trunnion block 2 forming a part of the breech casing is formed with an annular recess surround ing the barrel and the water jacket is pro-. vided with a bushing adaptedto enter the said recess and to serve as the bushing of a stuifin'g box or gland. Preferably there is an annular flange into which the rear end.

recess and preferably a second bushing 9 is provided in the recess for forming a rear abutment for holding the packing 10. When thewater jacket 5 is moved rearward by the attaching means the said packing 10 is compressed between the bushing 9* and the rear abutment, which has already been stated, may be a second bushing 9 Preferably the rear face of the bushing 9 is inclined rearward and outward and the front face of the bushing 9 is inclined forward and outward, the result being that there is a tendency to force the packm 10 inward and into firmer contact with the v arrel 1.

The-means for drawing the water jacket rearward and for holding it in the assembled position is preferably located entirely at one side of the jacket, preferably at the topthereof, so as to be more conveniently ace cessible. The attaching means may comprise a single bolt 11 arranged conveniently at the top of the gun and passing as shown throughan opening in an upwardly projecting lug 12 on the flange 9 and through a similar lug 13 secured to the top of the trunnion block of the breech casing, as shown in Fig. 8. Since the waterjacket 5 is centered on the barrel at the front, by means to be described, and at the rear by the bushing 9, it will be evident that. this connection is s'ufiicient and provides 2. In an automatic gun having a recoiling barrel, a frame supporting the barrel, a cooling jacket surroundingsaid barrel and slidable off the barrel in a forward direction, and a readily detachable connection between said jacket and said frame, the

said connection being operative while the.

4. In an automatic gun, havinga recoiling barrel, a frame supporting the barrel, a cooling acket surrounding said barrel and slidable off the barrel in a forward direction,- and a readily detachable connection between said jacket and said frame, the said connection comprising lugs on the jacket and the frame respectively, and a bolt extending through holes in the said lugs.

5. In an automatic firearm having are- I coiling barrel, a frame supporting thebarrel, a cooling jacket surrounding said barrel and slidable off the barrel in a forward direction, a readily detachable connection between said jacket and said frame, the said connection being operative while the casing is held against rotative movement, anda stuffing box surrounding said barrel and;

forming a fluid tight joint between said jacket and said barrel.

6. In an automatic firearm having a recoiling barrel, a frame, a cooling jacket surrounding s'aid barrel and slidable'off the barrel in aforward direction, a stuffing box surrounding said barrel and adapted to form a fluid tight joint between said jacket and said barrel, and a common means for detachably connecting the jacket to the frame and for adjusting the said stuffing box.

7. In an automatic firea-rm having arecoiling barrel, a frame, a cooling jacket supported by said frame and said barrel, the rear wall of said jacket forming a bearing bushing for the barrel, an abutment in the rear of said bushing in fixed relation to the frame, a packing between said abutment and the rear wall of the jacket, and means for moving the said jacket to compress said packing between the rear wall of said casing and said abutment.

S. In an automatic gun having a recoiling barrel, :1 frame supporting and guiding said barrel, a cooling jacket surrounding said barrel forwardly of said frame, a bushing surrounding said barrel adjacent to the rear wall ofsaid jacket, a packing between said bushing and the front wall of said frame, means for securing said jacket to said fram the actuation of d one sideof the neeaazwv securing meanscompressing said packing to form a fluid-tight oint. I

9. In an automatic gun having a recoiling barrel, .a breech of which is provided with an annular recess surrounding the barrel, a cooling acket sup ported on said barrel at the front and at.

the rear,'a packing in the recess, means on the rear wall of the jacket for con'ipressing said packing when the jacket is attached to the breech casing,.and a readily detachable means for attaching said cooling jacket to said breech casing.

10. In an automatic firearm having a recoilingrbarrel, a breech casing, a cooling jacket supported by said breech casing and said barrel, the rear wall of .said, jacket forming a bushing, an annular abutment at therear of the said bushing, a packing be,- tween the bushing and the abutment, and

a readily detachable connection between the said jacket and'the said breech casing, the

said connection being operative while the,

the rear of the said bushing, a packing be tween the bushing and the abutment, and a readilydetachable connection between the said jacket and the said breech casing, the said connection comprising lugs on the jacket and the frame respectively and a bolt extending throiwh holes in thesaid lugs and the said connection serving not only to hold the jacket but also to compress the said packing to form a fluid-tightjoint.

, 12. In an automatic gun having a recoiling barrel, a frame, a cooling jacket detachablysecured to said frame and surrounding said barrel, a front wall on said jacket, a bushing surrounding said barrel adjacent to said front wall, paekingin saidbushing, an annular member detachably secured to the front portionof said jacket by longitudinal movement of said member, and a gland-bushing su )plen'1ental to the said member whereby said packing is compressed to form a water-tight joint when said mem be]? is secured. to said jacket.

13. In an automatic gun having a recoiling barrel, a cooling jacket surrounding the barrel having a front wall adjacent the forward end of the barrel, an annulus surrounding the barrel adjacent the front wall and secured thereto, external screw threads on said front wall portion of the jacket, a cap with-internal threads engaging said external threads, packing forwardly of said annulus, and a g andushi g be ween said packing casing, the forward wallpacking to form a fluidand said cap whereby when said cap is secured to said front wall portion the glandbushing will compress the packing against the annulus forming a fluid-tight joint.

14:. In an automatic firearm having a barrel adapted to recoil upon the firing of a shot, of a single tubular jacket surrounding the barrel and adapted for holding cooling water, and a one-way valve associated with the partition for permitting free flow of the water from the. rear compartment to the front compartment and'for preventing free flow from the front compartment to the rear compartment.

15. In an automatic firearm having a barrel adapted to recoil upon the firing of a shot and being of larger diameter at its rear portion than at its forward portion, a tubular water-cooling jacket surrounding the barrel, RDClIllGELIlS for retaining the water in the front portion of the jacket upon the recoil when the arm is fired at angles of elevation.

16. In an automatic firearm adapted to be fired at angles of elevation and having a recoiling barrel of larger diameter at its rear portion than at itsforward portion, a cooling jacket surrounding the barrel, a one-way valve forming a partition some distance in rear of theforward wall ofsaid jacket to prevent the drop of the water level in the forward portion of the casing when the barrel recoils while being fired at angles of elevation.

17 In an automatic firearm having a barrel adapted to recoil upon the firing of a shot and being of larger diameter at its rear portion than at its forward portion, a

tubular water-cooling jacket surrounding the barrel, and means for preventlngtheclrop of the water level in the front portion of the jacket upon the recoil of the barrel when tiredat angles of elevation, said means comprising an annular member secured to the inside of the jacket and extending inward toward the barrel, but leaving a passage between it and the barrel for the free passage of water past said member, and a second annular member forward of the first member and adapted to have limited'longitudinal movement to open and close said passage, whereby in the recoil of the barrel said passage is closed and the water retained in the forward portion of the jacket to effectively subject the forward end of the barrel to its cooling action.

18. In anautomatic firearm having a barrel adapted to recoil upon the firing of a shot and being of larger diameter at its rear portion than at its forward portion, a tubular water-coohng acket surroundlng the barrel, and means for retaining the water in the front portion of the jacket upon the,

recoil and return of the barrelwhen the arm 1s fired at angles of elevation, said means comprising a fixed annulus secured to the wall of the jacket, and a movable annulus forward of said fixed annulus'and movable to open and close an annular passage for the water between the fixed annulus and the barrel, and means on the fixed annulus for guiding the movable annulus in its movement and for limiting such movement.

This specification signed and witnessed this 30th day of September A. D. 1925.

i i J OHN M. BROWNING.

CERTIFICATE OF CORRECTION.

Patent No. 1,666,887. Granted April 24, 1928, to

.JOHN M BROWNING.

It is hereby certified that error appears in the printed-specification of the above numbered aatent requiringcorrection as follows: Page 1, lines 89 and 90, for the article "the" read "a"; page 2, line 52, for the'word "bringing" read "to bring"; page 4-, line 55, claim 7, and page 5, line 32, claim 16, for the word "casing" read "jacket"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent-Office;

Signed and sealed this 3rd day of July, A. D. 1928.

, M, J. Moore, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,666, 887. Granted April 24, 1928, to

...JOHN M, BROWNING.

It is hereby certified that error appears in the printed-specification of the above numbered patent requiring correction as follows: Page 1, lines 89 and 90, for the article "the" read "a"; page 2, line 52, for theword "bringing" read "to bring"; page 4-, line 55, claim 7, and page 5, line 32, claim 16, for the word "casing" read "jacket"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent-Office, A

Signed and sealed this 3rd day of July, A. D. 1928.

. M. J. Moore, (Seal) Acting Commissioner of Patents. 

